if [[ -z "$line" ]]; then continue; fi;
### check size limit
sample_act_space="$(du -bd1 "$BKFEH_SAMPLE_DIR" | cut -f1 )"; # actual used space
cand_space="$(du -bd1 "$line" | cut -f1 )"; # size of candidate file to add
sample_req_space="$((sample_act_space + cand_space))";
if [[ -z "$line" ]]; then continue; fi;
### check size limit
sample_act_space="$(du -bd1 "$BKFEH_SAMPLE_DIR" | cut -f1 )"; # actual used space
cand_space="$(du -bd1 "$line" | cut -f1 )"; # size of candidate file to add
sample_req_space="$((sample_act_space + cand_space))";